Film-making process



NW. 4?, m4. 1,5142% J. H. HASTE FILM MAKING PROCESS Filed April 14, 1923 INVENTOR. James 517x536,

ATTONEY Patented Nov. 4, 1924..

warren JAMES H. HASTE, F ROCHESTER,- NEW YORK, ASSIGNOR 'I'O EASTMAN KODAK COM- lPAJ'ATY, OF ROCHESTER, NEW YORK, A CORPORATION OF YORK.

FILM-MAKING riaocnss.

Application filed April 14, 1923. Serial No. 632,156.

To all whom it may concern:

Be it'known that I, JAMEs H. HASTE, a citizen of the United States of America, residing at Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Film-Making Processes, of which the following is a full, clear, and exact specification.

This invention relates to processes of making film in which cellulosic solutions or dopes are deposited or flowed on to a filmforming face, the resulting film being stripped from such face upon evaporation of the solvent. One object of the invention is to provide a relatively simple film making process in which the film-forming face is not deteriorated in spite of the fact that the chief film making material tends to cause such deterioration. Other objects will hereinafter appear.

In the accompanying drawing Fig.1 is a diagrammatic side elevation, partly in section and on a' reduced scale of a typical film making apparatus in which my invention may be carried out, certain parts being exaggerated in relative size for the sake of clearness.

Fig. 2 is a fragmentary sectional'view of a film-forming face which may be employed in my process.

. Films such as those employed as supports for photographic coatings are made from cellulosic dopes,-that is, solutions of such substances as cellulose nitrate, cellulose acetate or cellulose ether, these solutions containing various modifying substances.-

For example, a-cellulose nitrate dope may include fusel oil and a little camphor, together with such volatile solvents as methyl alcohol and acetone. Examples of typical cellulose acetate and cellulose ether dopes will be found in U. S. Patents Nos. 1,342,601,

- Seel, June 8, 1920, and 1,217,027, Lilienfeld,

Feb. 20, 1917, respectively.

These dopes are customarily deposited in layers on smooth faces until enough ofthe volatile ingredients have evaporated to leave films that can be stripped off. Anendless first station to the second. In this way continuous strips of film are produced that are the face a section of the continuous film is formed and stripped off once during each cycle of movement of the face. The repetition of this action for a large number of times subjects the face to a severe test that tends to develop defects.

Since the film is formed in intimate contact with the face, which is as smooth and polished as possible, it reproduces the surface much as a casting reproduces a mold. But if the face deteriorates so that its normally smooth surface becomes pitted or contains line depressions, then corresponding protuberances or ridges will be formed on one face of the film. Furthermore, depressions in the face may expose minute areas of metal underneath the normal face, said 7 metal being of a nature which reacts with the dope to form compounds that enter into the film in minute quantities and impair sensitive thereover.

The face most often proposed for the formation of film is highly buffed or smoothed nickel-plated copper. But it has been found that certain cellulosic dopes, like cellulose acetate, which are becomin of increasing importance, are capable un er film-making conditions of deteriorating such nickelplated copper faces. It is, therefore, highly desirable to provide a process by means of which cellulose acetate films may be produced on such surfaces without deteriorating them.

I have discovered that such a process may be carried out by coating the face with a thin protecting covering before the deleterious dope is spread thereover to form the main body of the film. The protective coating unites with the main layer and forms therewith the transparent sheet or film which is stripped off from the face.

By way of illustration, I shall describe one embodiment of my invention in which the protective coating is formed from a nitrocellulose dope while the main part of the film is prepared from a cellulose. acetate dope, it being understood that my invention is not limited to such example, except as indicated in the appended claims.

photographic coatings spread v thin film 32. This dope mayconveniently be one of the usual 'Iiitrocellulose film making compositions which are well known to those skilled in the art.

As the wheel 1 is rotated in the direction of the arrow 11, the protective coating 32 is carried beneatha second dope-applying station 4 which may also comprise the usual trough from which the chief film-forming material is deposited through a slot in the bottom on to the protective coating. The conditions are such that the layer 42 formed from deleterious material 41 at station 4 is much thicker than the protective coating'32.

In the preferred embodiment of my invention I use a cellulose acetate. dope at station 4. The coating 32 and the layer 42 units into one substantially integral transparent film 52 which is stripped off from the face of wheel 1 at a roll station 5.

The nickel coating 6 is satisfactorily resistant to nitrocellulose compositions andconsequently remains in good condition for over verylong periods as long as coating 32 is applied to it and then stripped ofl". Since the layer 42 of deleterious material does not directly contact with the face, it is, so to speak, insulated from it as far as harmful efi'ects are concerned. Of course, the nitrocellulose coating, which is very thin, in y contain high percentages of infiammability reducing materials, such as triphenyl' phosphate, tricresyl phos hate, monochlornaphthalene, etc., as will e understood by those skilled in the art. While I have described an example of my process in connection with a nickel-plated copper wheel, the principle thereof is applicable wherever the chief filmforming ingredients have a tendency to deteriorate the particular film-forming face which is employed, a suitable thin protective coating being first applied to the face.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The process of producing film, made chiefly from a'cellulosic dope capable under film-making conditions of deteriorating the face on which said film is formed, which comprises the steps of forming a thin protecting coating on said face from a cellulosic 'dope that does not deteriorate said v face, forming a thicker coating from said firstnamed dope on said protecting coating, uniting said coatings, and finally stripping the united coatings from said face.

2. The process of producing transparent filmhmade chieflydrom axcellulose acetate dope capable under film-making conditions forming face, which comprises the steps. of first forming a thin transparent protecting coating on said face from a nitrocellulose dope that does not deteriorate said face, forming a thicker transparent coating from said cellulose acetatedope on said protecting coating, uniting said coatings to form a transparent film, and finally stripping said film from said face.

3. The process of producing film mad chiefly from a cellulosic dope capable under film-making conditions of deteriorating a metallic face on which said film is formed, which comprises the steps of forming a thin protecting coating on said metallic face from a cellulosic dope that does not deteriorate said face, forming a thicker coating from said first named dope on. said protecting coating, uniting said coatings, and finally st-rgppm the united coatings from said face.

igne at Rochester, New York this 11th day of April, 1923.

of deteriorating a nickel-plated copper film- I JAMES H. HASTE. I v 

